Convector plates for coil annealing apparatus



June 4, 1968 R. I... JONES ETAL 3,336,721

I: CONVECTOR PLATES FOR COIL ANNEALING APPARATUS Filed Dec. 20, 1965 2 Sheets-Sheet 1 -4llllllll1lllll u n um u u n;

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June 4, 1968 R. 1.. JONES ETAL 3,386,721

CONVECTOR PLATES FOR COIL ANNEALING APPARATUS 2 Sheets-Sheet 2 Filed Dec. 29, 1965 INVENTOR.

assent iatented June 4, 1958 3,386,721 CONVECTOR PLATES FOR COIL ANNEALING APFARATUS Robert L. Jones and Frank D. Hazen, Pittsburgh, Pa, as-

signors to Hazen Engineering Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Dec. 20, 1965, er. No. 515,523 1 Claim. (Cl. 263-47) ABSTRACT OF THE DlS CLOSURE This disclosure relates to new and useful improvements in convector plates for use in coil annealing apparatus, which, when stacked between or above coils of steel strips or sheets, provides for a constant velocity flow of the hot gases passing between the coils.

The flow passages of the convector plates are constituted by curved strips mounted on opposite sides of the plate, the strips being spaced a distance equal to the width of the strips and arranged on opposite sides so that the strip on one side will be in alignment with the space on the other to provide for maximum heat transfer from the gases passing through the flow passages.

The invention will become more apparent from a consideration of the accompanying drawings constituting a part hereof in which like reference characters designate like parts and in which:

FIGURE 1 is a vertical cross-section view, partially in elevation, of a coil annealing apparatus utilizing convector plates embodying the principles of this invention;

FIGURE 2 is a top plan view of a convector plate with curved flow passages embodying the principles of this invention;

FIGURE 3 is a cross-sectional view through a portion of the plate; and

FIGURE 4 is a cross-sectional view of a top convector cover plate.

In FIGURE 1 of the drawing, the numeral 1 designates coiled strips of steel or other metal sheet material having convector plates 2 and 3 disposed therebetween. A cover convector plate 4 is provided at the top of the stack of coils. The coils are mounted in a metal housing 5 constituting an inner cover and an insulating jacket 5a surrounds the inner cover 5 in spaced relation therewith. The cover 5 and jacket 5a are mounted on a base 6 and sealed at 7, the jacket 5a being provided with ears 8 for engagement by crane hooks to remove it from and lower it on the coils. Hot gases are supplied through a nozzle 9 extending through the base 10 of the annealing apparatus and a supporting hearth or plate 11 is provided with radial flow passages 12 to support the coils and provide for the return flow or recirculation of the heating and cooling gases which exit through an outlet 13. The apparatus, per se, is no part of the present invention and is merely shown to illustrate the location and function of the convector plates 2, 3 and 4.

As shown by arrows, hot gases are supplied through the nozzle 9 to the eye of the stacked coils from which the gases pass through openings 2a and 3a of the convector plates 2, 3 and 4, as shown by arrows, to the space between the coils and the housing wall 5. The gases travel downward to the passages 12 of the supporting base 11 and thence through the outlet 13 back to the heating or cooling device, the gases being recirculated through the eye of the coils, thence through the convector plate passages and to the space between the coil and housing, as

shown by arrows.

The invention resides in providing for the fiow of the gases from the eye of the coil through the convector plate at a uniform or constant velocity. To this end, the plate, which is designated by the numeral 15, is provided with curved strips 16 that may be fastened to the plate 15 in any suitable manner, as by welding or by screws, or they may be integrally cast with the disc or plate 15. As shown in FIGURE 3, the strips are disposed on both sides of the disc 15 so that they are staggered to bring the strip 16 on one side in alignment with the space or flow passage 17 on the other side, and in the top or cover convector plate 4 of FIGURE 1, the strips 16 are only provided at the bottom side of the plate.

The curve of the strips is designed so that the width of the strip, as well as the width of the slot between the strips, is constant from the inside to the outside diameter of the plate 15. The curvature of the strip allows for more travel of the gases with respect to the end faces of the coils with which they contact, but in addition, by maintaining the uniform width of the strip and slots, the constant velocity fiow is assured, which is of great importance in coil annealing apparatus, for the reason that the velocity of the annealing gases entering the eye of the coil is reduced, as is also the pressure, by the passing of the gases through the passages 17 of the convector plates. This is important because the gases must be sealed, as shown at '7, which is difiicult if there is too much pressure on the gas as it comes back to recirculate through the radial passages 12 to the center of the eye. The width of the strips and spaces is designed to provide maximum contact of the gases flowing through the pas sages with the faces of the coils and-they may be varied in curvature or shape to carry out this function.

Although one embodiment of the invention has been erein illustrated and described, it will be evident to those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

We claim:

1. In coil annealing apparatus, convector plates for mounting between the coils, said plates having curved flat strips of metal on opposite sides spaced to constitute flow passages for gases when disposed between the coils, the strips on one side being in alignment with the passages on the other side of said plates and the width of the strips and passages being equal to provide uniform velocity flow.

References Cited UNITED STATES PATENTS 2,489,012 11/1949 Dailey 26347 2,671,656 3/1954 Winder 263-47 2,904,325 9/1959 Jones et a1. 263-47 JAMES W. WESTHAVER, Primary Examiner. 

